The present invention relates to a magnetic head support mechanism for a magnetic disk drive and more particularly to a magnetic head support mechanism with a loading/unloading mechanism which reduces deformations of and damages to a gimbals during unloading and has excellent impact resistance during operation.
In a magnetic disk drive with a conventional loading/unloading mechanism, as disclosed in JP, 8-255320, A a tab provided to the front end of a suspension rides over an inclined portion of a parking mechanism when a disk stops, thereby preventing a contact between a slider and a disk. This eliminates a problem of the slider sticking to the disk due to their contact (the slider and the disk get stuck together, resulting in the disk failing to rotate or the slider failing to float).
To realize a uniform floating distance (height of the slider from the disk surface) over the entire surface of the disk, the slider of recent years employs a negative pressure. The slider using a negative pressure (referred to as a negative pressure slider), as disclosed in U.S. Pat. No. 4,420,780, has a pocket formed in that surface of the slider facing the disk to generate a pressure lower than the atmospheric pressure (negative pressure) to make uniform the floating force that would otherwise vary depending on the position along the disk radius, thereby achieving a uniform floating distance.
A problem addressed by the present invention is that, where the conventional negative pressure slider is used as the suspension for the loading/unloading mechanism, the slider stays on the disk surface due to the negative pressure while in an unloaded state and the application of a separation force overcoming the negative pressure may deform the gimbals.
An object of the present invention is to prevent the gimbals of the suspension from being deformed and damaged during unloading.
To achieve the above objective, the magnetic head support mechanism, which has a magnetic head carrying slider and a suspension that holds the slider against the disk surface from the back of the slider (i.e., from the side opposite the disk facing side), is characterized in that the suspension has a gimbals (also called a flexure) and a load beam and that the load beam is provided at its front end with a first tab and the gimbals is provided at its front end with a second tab. Outside the disk of the magnetic disk drive, a loading/unloading inclined portion (hereinafter referred to as a ramp) is provided. The ramp has a first ramp and a second ramp corresponding to the first tab and the second tab. During the loading/unloading operation, the first tab pulls the load beam away from the disk surface and the second tab pulls the slider away from the disk surface. This allows the loading/unloading operation to be carried out without deforming the gimbals even when the negative pressure slider is used.
Further, the friction of sliding portions as well as dust produced in the sliding portions can be reduced by applying a lubricating film or lubricating agent to one or both of sliding surfaces between the first tab and the first ramp and between the second tab and the second ramp, or by forming the sliding surfaces from a material excellent in the lubrication performance. With this arrangement, dust no longer adheres to the slider or causes floating height variations, assuring high reliability.
Further, the ramp is formed so that the second ramp begins at a position behind where the first ramp begins. So, when the disk rotation stops, the first tab and the first ramp contact first, followed by the contact between the second tab and the second ramp. In other words, the first tab lifts the load beam first and then the second tab lifts the slider. Therefore, the slider can be pulled up with a zero slider pressing load.
As a result, the slider can easily be pulled up and the wear of the second ramp can be reduced. During the loading operation, the slider is first lowered (or loaded) onto the disk surface and is then applied with a load. It is therefore possible to prevent damages which would otherwise be caused by the slider contacting the disk.
Because the first tab is formed longer than the second tab, the second ramp does not need to be formed directly below the first ramp. In other words, the second ramp can be formed by the side of the first ramp, which enables the ramp to have a sufficient strength.